Water treating apparatus



March l5, 1949. J. F. sEBALD WATER TREATING APPARATUS 3 ShetS-Sheet lFiled Feb. 13, 1947 3W joseph F. Sb@ ld March 15, 1949. F, SEBALD2,464,617 l WATER TREATING APPARATUS Filed Feb. 13, 1947 3 Sheets-Sheet2 Fae.; 1 joSePhF Sebclld March 15, 1949. J. F. sEBALD 2,464,617

l WATER TREATING APPARATUS Filed Feb. 13, 1947. 3 Sheets-Sheet 3 josephmgm@ IN V EN TOR.

Patented Mar. 15, 1949 2,464,617 WATER TREATING APPARATUS Joseph F.sebala, Bloomfield, N. J., assigner to and Machinery Corpora-Worthington Pump tion, Harrison, ware N. J., a corporation ot Dela-Application February 13, 1947, Serial No. 728,216 17 Claims. (Cl.210-16) This invention relates :to water treating apparatus and. moreparticularlyl to an improved cold process4 apparatus for softening,clarifying and purifying water.

The present invention embodies the advantages of the known fact that toadd raw water Iand chemicals to a slurry containing previouslypreci-pitated particles improves and accelerates coagulation andpurification and accelerates the chemical and physical changes involvedinseparating out the formed substances or solids. The newly formedsolids deposit by -accretion upon the particles present in the slurryrather than separating out as new small particles. These particles arerelatively stable, being not readily subject to disintegration, and ofsuch nature that clear treated water is readilyseparated from theslurry.

An object of the Ipresent invention is to provide an improved apparatusoperating on the principles above outlined which thoroughly mixes rawwater, chemicals, and slurry by means of a novel type of impellerstructure so as to rapidly and effectively precipitate-foreign materialfrom the water.

Another object of the invention is :to provide in an a-pparatus of thetype speciiled means whereby the amount of recirculation of partiallytreated Water, chemicals, and precipitated particles, may be varied soas to adapt the appara- :tus to variations in the'composition of rawwater being treated without loss of efficiency.

Another object of the invention is Ito incorporate in an apparatus ofthe type speciiled, stationary means utilizing the velocity of theeiiiuent :to impart a rotary motion to the effluent rising through thesettling chamber to increase the length -of passage and duration ofsettling action therein.

Another object is to embody in an apparatus of the type describedfeatures providing substantially constant ilow of water through theapparatus, controlled -concentration of slurry, and removal of sludgeaccumulations from the bottom of the water treating receptacle.

With these and other objects in view as may -a-ppear from theaccompanying specication, the invention consists of various features ofconstruction and combination of parts, which will be rst described inconnection with the accomp-anying drawings, showing a water treatingapparatus of the preferred form embodying the invention, and thefeatures forming the invention will be specifically pointed out in theclaims.

In the drawings:

Figure 1 is a vertical section through the improved water treatingapparatus.

Figure 2 is a horizontal section taken on the line 2--2 of Figure 1.

Figure 3 is a vertic-al section taken on the line 3-3 of Figure 2.

Figure 4 is a detailed longitudinal section of the pressure actuatedvalve.

Figure 5 is a detailed longitudinal section of the iioat level controldevice.

Referring more particularly to the drawings, the improved water treatingapparatus includes a. main body or ltreating receptacle I which isformed of an upper cylindrical Wall 2 and a lower cylindrical Wall 3joined by van inwardly and downwardly tapering annular wall 4. 'Iheupper portion of receptacle I has a treated water collection zone 5beneath which is the sedimentation or settling zone I6. The floc bed Iis formed at the top of the settling zone Ii. The treated w-ater risingthrough settling zoney 6 passesA through :the oc bed 1 and accumulatesin collection zone 5 from-which it passes over the top serrated edge 8vof the receptacle I into the annular treated water storage compartment9. The storage compartment 9 has an outlet I0 through which treatedwater is drawn for use `as desired.

Centrally located and suitably supported within the receptacle I is acylinder II forming the mixing chamber I2. Raw water to be treated isdelivered from-its source (not shown) -through the inlet pipe I3 to theraw water inlet I4 of the mixing chamber I2. Chemicals for precipitatingthe hardness imparting constituents from the raw water are deliveredfrom their source (not shown) through a suitable inlet pipe I5 to thechemical inlet I6 ofthe mixing vchamber I2. Circumferentially spacedabout the cylindrical wall II of the mixing chamber I2 are a pluralityof slurry admitting openings Il through which a.

predetermined 4amount of slurry passes from the settling zone 3 formixture with thechemicals and water inthe mixing chamber I2. The slurry,containing previously precipitated particles, provides nuclei for theformation of solids resulting from the reaction of the chemicals and thehardness imparting constituents of the water, thereby facilitatingprecipitation and hastening the treating process.

The upper end of the mixing chamber I2 has an inlet I8 for therecirculation of treated water therein, to be hereinafter described, andthe lower end has an outlet I9 for the eilluent contained therein. Therst pumping section 20a of the impeller structure 20 is located at theoutg ,water, chemicals, and precipitated lparticles of foreign material.

The impeller structure 20, as shown in its preferred form in Figures 2and 3, has three annular pumping sections each consisting of a pluralityof vanes rigidly assembled or integrally cast with the shroud rings 2|.The vanes 20a carried by the inner pumping' section 20a and the vanes20c carried by the intermediate pumping section 20c produce ilow in adownward direction and their combined outputequals the maximum output ofthe softener and isless than the output of the outer pumping section 20hcarrying vanes 2Ilb producing flow in an upward direc,- tion. Theimpeller structure isrigidly iixed by suitable means (not shown)familiar .to those skilled in the art to the drive shaft 22, the lowerend of which is carried by thrust bearing 23 mounted on the hollowbearing mounting 24 fixed to the bottom 25 of the receptacle I. The

drive shaft 22 extends upwardly through mixing chamber I2 to theexterior. of thetank. Suitable means are provided for rotating shaft 22at' 3o variable speeds, such as the motor 26 acting through the Variablespeed transmission 21 to drive bevel gear 26 engaging bevel gear 29fixed on the upper end of shaft 22. The driving means may be supportedas indicated on the top of stor-v age compartment 9 or by other suitablestructure (not shown). i

Upon rotation of the impeller structure 20, eiiluent is pumped bysection 20a from the mixing chamber I2 downwardly into the rstrecircula- 40 the design of their vanes and by the speed of ro-` tionchamberv 30. The rst recirculation 4chamber 30 is formed by the bottom25 of the receptacle I and the vertical cylindrical wall 3| ilxedthereto. The wall 3l is of slightly larger diameter vthan theimpellerstructure 20 and extends upwardly to substantially thehorizontal plane in which the lower end of the mixing chamber I2 lies.The effluent in rst recirculation chamber 30 ilows outwardly to theinlet of outer pumping section 20h which pumps it uipwardly into thesecond recirculation chamber 32.

The second recirculation chamber 32 is formed by the cylindrical wall IIof the mixing chamber I2 encircled by the upper end of an outwardly anddownwardly tapering annular wall 33 joined at its lower end by avertical downwardly extending cylindrical wall 34. The cylindrical Wall34. is of larger diameter than cylindrical wall 3| and forms therewithan annular outlet passage 35 from the second recirculation chamber 32opening into the annular space 36 formed'by the bottom 25 of thereceptacle I, vertical cylindrical wall 3|, and the lower cylindricalwall 3 of the receptacle I. An annular passage 31 formed by verticalcylindrical wall 34 and lower cylindrical wall 3 of the receptacle Ipermits flow of eilluent from the annular space 36 into the annulartrough-like bottom portion, formed by the cooperating tapering walls land 33, of the settling zone 6.

The uipwardly pumping section 20h is designed to have a greater capacitythan the downwardly pumping section 20c and therefore the amount ofeffluent pumped by section 20h into the second recirculation chamber 32exceeds the capacity of section 20c. The excess eiiluent is forced outthrough the annular outlet passage 35 and the I remainder is pumped bysection 20c downwardly backl into the first recirculation chamber 30.The impeller structure is designed so that the amount of eiliuentrecirculated by the section 20c is several times greater than thatforced through outlet 35 oi' the settling zone 6 or that pumped bysection 20a from the mixing chamber I2 into the first recirculationchamber 3U. Such recirculation of the eilluent consisting of ypartiallytreated water, chemicals. and previously precipitated particles,provides thorough and intimate mixing of the constituents of theeilluent and increased opportunity for the precipitation and growth ofthe particles of foreign material separated from the water being treatedby the action of the chemicals.

The optimum amount of recirculation per unit interval of time, or rateof recirculation, may vary with the composition of the Water beingtreated. It is therefore desirable in an apparatus of this type to beable to control the rate of recirculation so as to most efilcientlytreat water having varying types and degrees of hardness. Provision ismade in this apparatus for controlling the rate of recirculation as willbe presently described.

The output of the inner pumping section 20a is governed by the volume ofeffluent available in the mixing chamber I2 and the vanes 20a' aredesigned so that the section 20a has a tendency to operate at more thanfull capacity at all speeds of rotation. Because of this, as well as atreated water recirculation feature to be hereinafterV described, therate of iiow through the mixing chamber l2 may be controlled byregulating valves so as to be substantially constant regardless ofrotational speed. Thus the outputs of pumping sections 2Gb and 20c aregoverned by tation of the impeller structure 20. For a given speed ofrotation, the rate of recirculation between recirculation chambers 30and 32 depends upon the design of the respective vanes 20h and 20c; andfor given vane designs, the rate of this recirculation may be varied byvarying the speed of rotation of the impeller structure 20.

In the installation of the improved water treating apparatus theimpeller structure is designed to give an optimum rate of recirculation,at a predetermined speed, for the type of water to be treated and thechemicals employed. Subsequent operation or variations in thecomposition of the water being treated may necessitate changes in thedegree of mixing or rate of recirculation to obtain the most efiicientoperation of the apparatus. As indicated this can be readily achieved byvarying the speed of rotation by means of the variable speedtransmission 21. It is to be understood that other variable speed meansfor driving the impeller structure 20 may be employed without departingfrom the spirit of the invention.

The etlluent forced out of secondrecirculation chamber 32 ilowsdownwardly through the annular passage 35 into the annular space 36wherein its direction of ilow is completely reversed and it ilowsupwardly through the annular passage 31. The annular passage 31 containsa plurality of xed ilow directing vanes 38 which transform the verticalvelocity of the effluent into a large horizontal velocity component anda smaller vertical component thus, in eiect, producing an upward spiralrotation of the eilluent I as it enters the settling zone 6. Reductionof the vertical velocity of the eilluent eliminates excessive localizedagitation of the iloc bed 1 and the spiral path followed by the eilluentrising through thesettling zone 6 provides it with maximum length oftravel and opportunity for the agglomeration` and `separation ofVprecipitated particles. The fioc bed 1 serves to filter out the foreignmaterial in suspension in the water and clarified. treated water risestherefrom into the collection zone from whence it flows into the storagecompartment 9; as previously described. A

It is desirable to maintain the level of the floc bed substantiallyconstant and prevent the excessive deposition of precipitated particleson the inner surfaces of the apparatus. Since the level of the fioc bedand the suspension of particles represents an equilibrium between thenatural gravitational forces acting downwardly on the particles and theupward force of the water rising through the apparatus, it is essentialthat these forces be kept substantially in balance. This can beaccomplished by recirculating treated water through the apparatus so asto maintain uniform flow regardless of demand and by removing sludge orprecipitated particles in sulcient quanoperated valve 42 in the sludgeoutlet line 43. A

sludge collection trough 44 is formed on the inner wall of thereceptacle I by a suitable partition 45 attached thereto and ispositioned to receive precipitated particles from the floc bed 1 or thesettling zone 6. The sludge trough empties at its bottom portion intothe sludge outlet line 43.

means of truncated conical section 55 to the cylindrical wall II at thetreated water inlet I6 of the mixing chamber I2. The manifold outletline 54 carries two valves, manually operated of rotation of theimpeller structure is varied.

1 one such valve.

Flow of raw water through the meter 39 actuates y the switch mechanism4|l which acting through the time delay relay 4| opens the solenoidvalve 42 permitting blow oil? of sludge through the outlet line 43 for aperiod depending upon the setting of the time delay relay 4|. Thus, thesludge removal is governed in accordance'with the rate of particleformation by the rate of raw water flowing into the apparatus.

An auxiliary sludge removal device is also provided for removing foreignmaterial which accumulateson the bottom 25 of the receptacle I in thefirst recirculation chamber 36. A plurality of radially extending pipes46 having downwardly disposed inlets 41 positionedy near the bottom 25of the receptacle I are carried by the hollow bearing mount 24 and haveoutlets 48 opening thereinto. A sludge outlet line 49 communicates withthe interior 56 of the hollow bearing mounting 24. Opening the valve 5|in the sludge outlet line 49 permits sludge from the bottom 25 of thereceptacle I to be forced through pipes 46 into the interior 56 of thebearing mounting 24 from which it flows to waste through outlet pipe 49.

The recirculation of treated water feature includes an annular treatedwater intake manifold 52 having a plurality of circumferentially spacedinlets 53 opening into the collection zone 5. A radially extendingmanifold outlet line 54 in the treated water collection zone 5 isconnected by Pressure actuated valve 51, which is' schematicallyillustrated exterior of the treating apparatus for the purpose ofclarity, is similar to pressure actuated valve 59 in. the raw waterinlet line I3, but

vreversely actuated. The pressure actuated valves 51- and 59 are of astandard type and may be purchased on the open market. Figure 4 shows Itconsists of a main body or housing 60 having a double-seated valve spool6I positioned therein to control the flow of water through the housing60 and consequently through ythe pipe I3. `The valve spool 6| isconnected to the diaphragm 62, located in the sealed housing 63, bymeans of the valve stem 64. The diaphragm 62 is urgedy to the valve openposition by the spring 65 but the pressure of air entering the housing63 through line 66 urges the diaphragm 62 to the valve close position.The flow of air through line 66 is controlled by the float level controldevice 61 which is also a standard unit which may be purchased on theopen. market. Figure 5 illustrates a float'level control device 61. Thedevice 61 includes a housing 68 connected 'by means of piping 69 to theinterior of the treated water storage compartment 9 so that Water mayowfrom compartment 9 into the housing 6'8 and actuate the float 1licarried therein. The float 10 is connected by a suitable lever partment9 through the vertical movement of float 10 and tends to close the valve59 in the raw water line I3 as the level of water rises in storagecompartment 9. Air flowing through line 66 also actuates the pressureactuated valve 51 but reversely to the actuation of valve 59 so that theflow of treated water through the recirculation manifold outlet line 54will be complementary to the flow through raw water inlet line I3 andsubstantially a constant predetermined quantity of water will flowthrough the apparatus regardless of the demand for treated water.

It is to be understood that the specific structure and arrangement ofparts enclosed may be widely modied within the spirit of the inventiondefined by the claims.

What is claimed is:

1. In a water treating apparatus, a receptacle, the upper portion ofsaid receptacle comprising a treated water collection zone and theportion beneath said upper portion including a settling zone whereinforeign material is precipitated from the water; said receptacle havingan outlet for treated water communicating with said treated watercollection zone; partitions within said receptacle forming a mixingchamber, first SAQQGI? and second recirculation chambers, andcommunicating means for the flow of effluent from said mixing chamberthrough said rst and second recirculation chambers to said settlingzone; means for admitting raw Water to said mixing chamber; means foradmitting chemicals to said mixing chamber; means for admitting slurryto said mixing chamber; an impeller structure having first, second, andthird pumping sections; each of said pumping sections being of annularform and having a plurality of iiow directing vanes; said pumpingsections being conicentrically disposed about and driven by a commondriving shaft; said pumping sections acting in substantially the sameplane; said iirst and third pumping sections producing iow of theeiiiuent in a direction substantially reverse to the direction of iiowproduced by said second pumping section; said first pumping sectionhaving its -inlet positioned at the outlet of said mixing chamber toreceive therefrom eiiiuent comprising water, chemicals, and slurry, saidrst pumping section discharging eiiiuent into said first recirculationchamber; said second pumping section having its inlet positioned toreceive eiiiuent from said first recirculation chamber and its outletpositioned for discharging eiiluent into said second recirculationchamber, means for guiding part of the discharge lfrom said secondpumping section into said settling zone; said third pumping sectionhaving its inlet positioned to receive eiiiuent from said secondrecirculation chamber and its outlet positioned for discharging eiliuent-back into said rst recirculation chamber: and means for operating saidimpeller structure.

2. In a water treating apparatus, a receptacle, the upper portion ofsaid receptacle comprising a treated water collection zone and theportion beneath said upper portion including a settling zone whereinforeign material is precipitated from the water; said receptacle havingan outlet for treated water communicating with said treated water-collection zone; partitions within said receptacle forming a mixingchamber, iirst and second recirculation chambers, and communicatingmeans for the flow of efiiuent from said mixing chamber through said rstand second recirculation chambers to said settling zone; means foradmitting raw water to said mixing chamber; means for admittingchemicals to said mixing chamber, means for admitting slurry to saidmixing chamber; an impeller structure having iirst, second. and thirdpumping sections, said pumping sections being concentrically disposedabout and driven by a common driving shaft; said rst pumping sectionhaving its inlet positioned at the outlet of said mixing chamber toreceive therefrom eiiluent comprising water, chemicals, and slurry, saidfirst `pumping section discharging eiiiuent into said firstrecirculation chamber; said second pumping section having its inletpositioned to receive efiiuent from said first recirculation chamber andits outlet positioned for discharging efiiuent into said secondrecirculation chamber, means for guiding part of the discharge from saidsecond pumping section into said settling zone; said third pumpingsection having' its inlet positioned to receive eiiluent from saidsecond recirculation chamber and its outlet positioned for dischargingefiiuent back into said rst recirculationt chamber; and means foroperating said impeller structure.

3. In a water treating apparatus, a receptacle,

the upper portion of said receptacle comprising a treated watercollection zone, andthe portion beneath said upper portion including asettling zone wherein foreign material is precipitated from the water:said receptacle having an outlet for treated water communicating Y withsaid treated water collection zone; partitions within saidreceptacle'forming a mixing chamber, first and second recirculationchambers, and communicating means for the flow of eiliuent from said'mixing chamber through said rst and second recirculation chambers tosaid settling zone;

vmeans `for admitting raw water to said mixing chamber: means foradmitting chemicals to said mixing chamber; means' for admitting slurryto said mixing chamber; an impeller structure having rst.' second andthird pumping sections; said pumping sections being of annular form andhav ing a plurality of iiow directing vanes; said first pumping' sectionhaving its inlet positioned at the outlet of said mixing chamber toreceive therefrom eiiiuent comprising lwater, chemicals,

and' slurry, Said rst pumping section discharging eiiluefnt into saidrst recirculation chamber; said second pumping section having its inletpositioned to receive eiiluent from said rst recirculation chamber andits outlet positioned for discharging eiiiuent into said secondrecirculation chamber and said settling zone; said third pump` o treatedwater collection zone: partitions within said,4 receptacle forming amixing chamber, iirst and second recirculation chambers, andcommunicating means for the flow of efiiuent from said mixing chamberthrough said first and second recirculation chambers to said settlingzone: means for admitting raw water to said mixing chamber; means foradmitting chemicals to said mixing chamber; means for admitting slurryto said mixing chamber; and impeller structure having iirst, second. andthird pumping sections; said pumping sections acting in substantiallythe same plane: said first and third pumping sections producing flow ofthe eiliuent in a direction substantially reverse to the direction offlow produced by said second pumping section; said iirst pumping sectionhaving its inlet positioned at the outlet of said mixing chamber toreceive therefrom eiiiuent comprising water, chemicals,

and slurry, said rst pumping section discharging eiiiuent into saidfirst recirculation chamber; said second pumping sectionvhaving itsinlet positioned to receive eiiiuent from said first recirculationchamber and its outlet positioned for discharging eiiiuent into saidsecond recirculation chamber, means Vfor guiding part of the dischargefrom said 'second pumping section into said settling zone: said thirdpumping section having its inlet positioned to receive eiiiuent fromsaid second recirculation chamber and its outlet positionedfor,discharging etiluent back into said first recirculation chamber; andmeans for operating said impeller structure.

5.'In a water treating apparatus, a receptacle, the upper portion ofsaid receptacle comprising a treated water collection zone and theportion beneath said upper vportion including a settling zone whereinforeign material is precipitated from the water; said receptacle havingan outlet for :treated water communicating with said treated watercollection zone; partitions within said receptacle forming a mixingchamber, first and second recirculation chambers, and communicatingmeans for the flow of effluent from said mixing chamber through saidfirst and second recirculation chambers to said settling zone; means foradmitting raw water to said mixing chamber; means for admittingchemicals to said mixing chamber; means for admitting slurry to saidmixing chamber; an impeller structure having firstsecon'd, and thirdvpumping sections; said rst pumping section having its inlet positionedat the outlet of said mixing chamber tol receive therefrom effluentcomprising Water, chemicals, and slurry, said first pumping sectiondischarging effluent into said first recirculation chamber; said secondpumping section having its inlet positioned to receive effluent fromsaid first recirculation chamber and its outlet positioned fordischarging effluent into said second recirculation; chamber, means forguiding part of the discharge from said second pumping section into saidsettling zone; said third pumping section having its inlet positioned toreceive effluent from said second recirculation chamber and its outletpositioned for discharging effluent back into said rst recirculationchamber; and means for operating said impeller structure.

6. In a water treating apparatus, a receptacle,

`beneath said upper portion including a settling zone wherein foreignmaterial is precipitated from the water; said receptacle having anoutlet for treated water communicating with said treated watercollection zone; an impeller structure having first, second, and thirdpumping sections; said pumping sections being concentrically disposedabout and driven by a common driving shaft; means for delivering waterto the inlet of said first pumping section; means for deliveringvchemicals to the inlet of said first pumping section; means fordelivering slurry to the inlet of said first pumping section; means fordirecting effluent discharged by said first pumping section to the inletof said second pumping section; means for directing a portion of theeffluent discharged by said second pumping section to the inlet of saidthird pumping section, means for directing the remainder of the eiliuentdischarged by said second pumping section to said settling zone; meansfor directing the effluent discharged by said third pumping section backto the inlet of said second pumping section; and means for operatingsaid impeller structure.

7. In a water treating apparatus, a receptacle, the upper portion'ofsaid receptacle comprising a treated water collection zone, and theportion beneath said upper portion including a settling zone whereinforeign material is precipitated from the water; said receptacle havingan outlet for treated water communicating with said treated watercollection zone; an impeller structure having first, second, and thirdpumping sections; said first and third pumping sections producing flowof the eilluent'in a direction substantially reverse to the direction offlow produced by said second pumping section; means Afor deliveringwater to the inlet of said first pumping section; means for deliveringchemicals to the inlet of said first pumping section; means fordelivering slurry to the inlet of said first pumping section; means fordirecting effluent discharged by said first pumping section to the inletof said second. pumping section; means for directing a portion of theeffluent dischargedby said second pumping section to the inlet of saidthird pumping section, means for directing the remainder of the effluentdischarged by said second pumping section to said settling zone; meansfor directing the effluent discharged by said third pumping section backto the inlet of said second pumping section; and means for operatingsaid impeller structure.

8. In a water treating apparatus, a receptacle, the upper portion ofsaid receptacle comprising a treated water collection zone and theportion beneath said upper portion including a settling zone whereinforeign material is precipitated from the water; said receptacle havingan out` let for treated water communicating with said treated watercollection zone; an impeller structure having first, second and thirdpumping sections; means ior delivering water to the inlet of said firstpumping section; means for delivering chemicals to the inlet of saidfirst pumping section; means for delivering slurry to the inlet of saidfirst pumping section; means for directing a portion of the effluentdischarged by said second pumping section to the inlet of said thirdpumping section, means for directing the remainder of the effluentdischarged by said second pumping section to said settling zone; meansfor directing the leflluent discharged by said third pumping sectionback to the inlet of said second pumping section; and means foroperating said impeller structure.

9. In a water treating apparatus, a receptacle,

-the upper portion of said receptacle comprising treated watercollection zone; partitions within said receptacle forming a mixingchamber, first and second recirculation chambers, and communicatingmeans for the flow of effluent from said mixing chamber to said settlingzone; means for admitting raw water to said mixing chamber; means foradmitting chemicals to said mixing chamber; means for admitting slurryto s'aid mixing chamber; an vimpeller structure positioned to receiveeffluent, comprising water, chemicals, and slurry from said mixingchamber. recirculate it through said first and second recirculationchambers, and discharge it into said settling zone; and means foroperating said impeller structure.

g from said mixing chamber to said settling zone;

auger? pumping the eilluent, comprising water, chemicals, and slurry.from said mixing chamber through said first and second recirculationchambers into said settling zone; said communicat in g means including asinuous annular passage in the path of the effluent pumped by saidmechanical means into said settling zone; said annular passage having aplurality of fixed flow directing vanes for imparting rotary motion tothe effluent entering said settling zone. y

11. In a water treating apparatus, a receptacle,'the upper portion ofsaid receptacle comprising a treated water collection zone, and theportion beneath said upper portion including a settling zone whereinforeign material is precipitated from the water; said receptacle havingan outlet for treated water communicating with said treated watercollection zone; partitions within said receptacle forming a mixingchamber, rst and second recirculation chambers, and communicating meansfor the ow of eiiluent from said mixing chamber to said settling zone;means for admitting raw water to said mixing chamber; means foradmitting chemicals to said mixing chamber; means for admitting slurryto said mixing chamber; an impeller structurepositioned to receiveeiiluent, comprising water, chemicals, and slurry, from said mixingchamber, recirculate it through said rst and second recirculationchambers, and discharge it into said settling zone; means for operatingsaid impeller structure; and means for imparting rotary motion to theeilluent entering said settling zone.

12. In a water treating apparatus, a receptacle, the upper portion ofsaid receptacle comprising a treated water collection zone, andtheportion beneath said upper portion including a settling zone whereinforeign material is precipitated from the water; said receptacle havingan outlet for treated water communicating with said treated watercollection zone; partitions within said receptacle forming a mixingchamber, rst and second recirculation chambers, and communicating meansfor the flow of eiiluent from said mixing chamber to said settling zone,means for admitting raw water'to said mixing chamber; means foradmitting chemicals to said mixing chamber; means for admitting slurryto said mixing chamber; a rotary impeller structure positioned toreceive eiiluent, comprising water, chemicals, and slurry, from saidmixing chamber,

recirculate it through said rst and second re` circulation chambers, anddischarge it into said settling zone;means for rotating said impellerstructure; and means for varying the speed of rotation of said impellerstructure so as to vary the rate of recirculation of elliuent throughsaid first and second recirculation chambers.

13. In a water treating apparatus, a receptacle, the upper portion ofsaid receptacle comprising a treated water .collection zone and theportion beneath said upper portion including a settling zone whereinforeign material is precipitated from the water; a treated water storagecompartment having an outlet for treated Water communicating with saidtreated water collection zone; partitions within said receptacle forminga mixing chamber, rst and second recirculation chambers, andcommunicating means for the ow of eiliuent from said mixing chamberthrough said first and second recirculation chambers to said settlingzone; means for admitting water to said mixing chamber; means foradmitting chemicals to said mixing chamber; means for admitting slurryto said mixing chamber; an impeller structure positioned to receive theefuent, comprising water, chemicals, and slurry from said mixingchamber, recirculate it through said first and second recirculationchambers and discharge it into said settling zone; means for operatingsaid impeller structure; means for recirculating treated water from saidtreated water collection zone back through said mixing chamber; meansreversely actuated by variations in the level of treated water in saidstorage compartment for regulating in complementary amounts the rawwater and treated water admitted to said mixing chamber so as tomaintain a substantially constant ilowv of water through the mixingchamber.

14. In a watertreating apparatus, a receptacle, the upper portion ofsaid receptacle comprising a treated water collection zone and theportion beneath saidupper portion including a settling zone whereinforeign material is precipitated from the water; a treated Water storagecompartment having an outlet for treated water communicating with saidtreated water collection zone; partitions within said receptacle forminga mixing chamber, rst and second recirculation chambers, andcommunicating means for the flow of eilluent from said mixing chamberrthrough said rst and second recirculation chambers to said settlingzone; means for admitting water to said mixing chamber; means foradmitting chemicals to said mixing chamber; means for admitting slurryto said mixing chamber; an impeller structure positioned to receive theeilluent, comprising water, chemicals and slurry from said mixingchamber, recirculate it through said rst and second recirculationchambers and discharge it into said settling zone: means for operatingsaid impeller structure; `means for varying the rate of recirculation ofeiiluent through said first and second recirculation chambers; means forrecirculating treated water from said treated water collection zone backthrough said mixing chamber; means reversely actuated by variations inthe level of treated water in said storage compartment for regulating incomplementary amounts the raw water and treated water admitted to saidmixing chamber so as to maintain a substantially constant ow. of waterthrough the mixing chamber; and means for manually regulating the amountof water recirculated.

15. In water treating apparatus, a receptacle, the upper portion of saidreceptacle comprising a treated water collection zone and the portionbeneath said water collection zone including la settling zone whereinforeign material is precipitated from the water, said receptacle havingan outlet for treated water communicating with said treated watercollection zone, partitions within said receptacle forming a mixingchamber, first and second recirculation chambers and communicating meansfor the flow of eilluent from said mixing chamber through said firstandsecond recirculation chambers to `said settling zone, means foradmitting raw water to said mixing chamber, means for admittingchemicals to said mixing chamber, means for admitting slurry to saidmixing chamber, an impeller structure having first, second and thirdpumping sections, said pumping-sections being concentrically disposedabout and driven by a common driving shaft, said iirst pumping sectionhaving its inlet positioned at the outlet of said mixingchamber toreceive therefrom a mixed eilluent comprising water, chemicals andslurry, said first pumping section discharging eiiluent into said firstrecirculation chamber, said second pumping section having its pumpingsection whereby only part of the eiiluent i pumped by the second pumpingsection will be returned to said first recirculating chamber and theremaining portion of eiiluent pumped by said second pumping section willbe delivered by said communicating means to said settling zone.

16. In water treating apparatus, a receptacle, the upper part of saidreceptacle forming a treated water collection zone and the portionbeneath said treated water collection zone including a set-,

tling zone wherein foreign material is precipitated from the water, awater storage compartment having communicationy with said treated watercollection zone and receiving treated water there-` from, saidreceptacle having an outlet for treated water communicating with saidwater storage compartment, an annular partition in said receptacleforming a mixing zone, a partition in said receptacle forming arecirculation zone, conduit means for delivering treated Water from saidtreated water collection zone into said mixing chamber, means foradmitting chemicals to said mixing chamber, means for admitting rawwater to said mixing chamber, said annular partition provided withopenings opening into said settling zone for admitting slurry into themixing chamber, and a pump at the outlet of said mixing chamber to pumpthe mixture of water, slurry, and chemicals into said recirculationzone, a partition in said receptacle forming a second recirculatingzone, a passageway communicating with said second recirculating zone andwith said settling zone, a second pump for pumping the mixture of waterand slurry from said rst recirculating zone into said secondrecirculating zone, and a third pump for pumping the mixture from saidsecond recirculating zone to said first recirculating zone, said secondpump having a greater capacity than said third pump whereby all of themixture pumped into the second recirculating zone from said firstrecirculating zone will not be returned thereto and the unreturnedportion of the mixture will pass through said passageway to saidsettling zone. l

17. In water treating apparatus, a receptacle, the upper part of saidreceptacle forming a. treated water collection zone and the portionbeneath said treated water collection zone including a settling zonewherein foreign material is precipitated from the water, a water storagecompartment having communication with said treated water iii) collectionzone and receiving treated water therefrom, said receptacle having anoutlet for treated water communicating with said water storagecompartment, an annular partition in said Yreceptacle forming a mixingzone, a partition in said receptacle forming a recirculation zone,conduit means for delivering treated water from said treated watercollection zone into said mixing chamber, means for admitting chemicalsto said mixing chamber, means for admitting raw water to said mixingchamber, said annular partition provided with openings opening into saidsettling zone for admitting slurry into the mixing chamber, and a pumpat the outlet of said mixing chamber to pump the mixture of water,slurry, and chemicals into said recirculation zone, a partition in'saidreceptacle forming a second recirculating zone, a passagewaycommunicating with said second recirculating zone and with said settlingzone, a second pump for pumping the mixture of water and slurry fromsaid first recirculating zone into said second recirculating zone, and athird pump for pumping the mixture from said second recirculating zoneto said first recirculating zone, said second pump having a greatercapacity. than said third pump whereby all of the mixture pumped intothe second recirculating zone from said iirst recirculating zone willnot be returned thereto and the unreturned portion of the mixture willpass through said passageway to said settling zone, a valve forcontrolling the quantity of raw water 'admitted intov said mixingchamber, a valve for controlling the quantity of treated water admittedinto said mixing chamber, pressure operated means for operating saidvalves, and means controlled by the level of treated water in said waterstorage compartment for controlling operation of said valves.

JOSEPH F. SEBALD.

REFERENCES CITED Thefollowing references are of record in the file Aofthis patent:

UNITED STATES PATENTS Green Oct. 21, 1947

